The following background information may present examples of specific aspects of the prior art (e.g., without limitation, approaches, facts, or common wisdom) that, while expected to be helpful to further educate the reader as to additional aspects of the prior art, is not to be construed as limiting the present invention, or any embodiments thereof, to anything stated or implied therein or inferred thereupon.
Typically, ergonomics is the practice of designing products, systems, or processes to take proper account of the interaction between them and the people who use them. Physical ergonomics is concerned with human anatomy, and some of the anthropometric, physiological and bio mechanical characteristics as they relate to physical activity. Certain jobs or work conditions cause a higher rate of worker complaints of undue strain, localized fatigue, discomfort, or pain that does not go away after overnight rest. These types of jobs are often those involving activities such as repetitive and forceful exertions; frequent, heavy, or overhead lifts; awkward work positions; or use of vibrating equipment. Often, office jobs create the greatest amount of injury to the lower back, spine, and legs, due to the repetitive nature of the tasks.
The typical office related chair is comprised of a seat of about 17″, but often up to 20″ or more, such that the user bears weight on the buttocks and ischia as well as the thighs. Such a design, however, puts pressure on the user's thighs and calves, affecting circulation to the legs and feet, and creating discomfort for the user. Further, the lumbar spine is encouraged into a position of extreme flexion known to create disc pathology, another source of much pain and lost work time. Efforts have been made to design ergonomic chairs that can at least partially offset these anatomical issues, and also to be more adjustable.
It is known that an ergonomic chair is designed ergonomically to distribute the weight of the occupant to various parts of the body. For example, a seat that is higher results in dangling feet and increased pressure on the underside of the knees. It may also result in no weight on the feet which means more weight elsewhere. A lower seat may shift too much weight to the seat bones. Generally, a reclining seat and back will shift weight to the occupant's back. This may be more comfortable for some in reducing weight on the seat area, but may be problematic for others who have bad backs. In general, if the occupant is supposed to sit for a long time, weight needs to be taken off the seat area and thus easy chairs intended for long periods of sitting are generally at least slightly reclined. Reclining may not, however, be suitable for chairs intended for work or eating at table. Thus, the ergonomic chair is also adjustable to accommodate for such deficiencies.
It is recognized that the ergonomic chair is not, however, always conducive to maintaining a proper posture while sitting at a workstation, walking between workstations, or picking up objects. Consequently, the spine may not be forced into the proper alignment. This is problematic because the spine has a proclivity to relax in a slightly slouched position, and consequently, the pelvic tilts forward. Generally, the curved nature of the spine in this slouched position may create stress on the lower back and the neck, especially after long durations and repetitive movements at the workstation. After a duration, this may result in spinal problems, lower back pain, sciatic nerve pain, general neck and spine pain, and sore legs—conditions that are not conducive to productivity and time at the workstation.
Other proposals have involved ergonomic chairs designed for repetitive tasks. The problem with these is that they are not conducive to sitting, standing, walking, bending, and climbing functions. Also, the lower back or the pelvis cannot be supported independently of each other to enhance support of the lower back and maintain the spine in a straight posture and create spacing between the posterior intervertebral discs. Even though the above cited ergonomic devices meets some of the needs of the market, a mobile body unweighted sit and stand chair assembly and method of operation that is used to support the lower back through weight alleviation is still desired.